1. Field of the Invention
The present invention relates to a new and improved latchable vacuum blanket frame assembly including a base supporting a glass panel and a vacuum blanket frame hingedly mounted along one side of the glass panel for movement between a closed position and an open, angularly divergent position elevated from a working face of the glass panel for loading and removing sheets of film media used for making copy sheets, with silk screen materials, photographic plates and the like.
More particularly, the latchable vacuum blanket frame system of the present invention is especially adapted to provide a latching mechanism that contributes to the operation of the vacuum blanket frame assembly when latching and unlatching the vacuum blanket frame and the glass panel.
2. Background of the Prior Art
Vacuum blanket frame assemblies have been used for obtaining precise registration between a film media master image sheet and a pre-sensitized image sheet while the sheets are sandwiched together between a flexible vacuum blanket and a glass panel for controlled light exposure. A primary function of a vacuum blanket frame assembly is to assure intimate contact between the materials during exposure in order to maintain image transfer integrity. Vacuum blanket frames are sometimes pivotally mounted on a support base structure and generally include a peripheral frame structure which carries a flexible vacuum blanket operable to press together film media sheets in close precision registration against the planar surface of a glass panel.
U.S. Pat. No. 3,738,742 discloses a photographic printer having a rectangular printing frame or base that is rotatably mounted in a cabinet containing a light source for movement between alternate positions for exposure of film media held in precise registration against a planar surface of the printing frame.
U.S. Pat. No. 4,028,166 discloses a system for laminating sheet material employing a rigid base structure and a hingedly attached rectangular frame with vacuum means for insuring accurate registration between media sheets placed thereon.
U.S. Pat. No. 3,627,416 discloses a contact printing employing twin frame structures for making photographic plates utilizing silk screen materials and the like.
Other photographic contact printers for silk screen materials and the like are shown in U.S. Pat. Nos. 3,399,584 and 3,266,402.
U.S. Pat. No. 1,151,477 discloses an exposing table employing a flexible vacuum blanket and U.S. Pat. No. 3,463,587 discloses a vacuum frame for silk screen materials having adjustable clamps for varying the amount of compression on a peripheral air and light seal.
U.S. Pat. No. 1,702,232 discloses a vacuum pressure printing frame having a cover plate cooperating with a flange of a sealing strip forming an air-tight chamber around a negative and a press plate and U.S. Pat. No. 4,536,085 discloses a multiple vacuum frame unit including a glass frame pivotally mounted on a base and a blanket frame pivotally connected to the glass frame.
U.S. Pat. No. 4,664,511 discloses a registration board capable of dissipating static electricity through a conductive sink in a vacuum frame exposure system, and U.S. Pat. No. 3,147,683 discloses a photographic printing apparatus for "step and repeat" printing processes.
U.S. Pat. No. 4,575,233 discloses a photographic printer for exposing both sides of printed circuit boards and U.S. Pat. No. 4,989,035 discloses a latch and lifting system for a vacuum frame assembly employing a common lift member for operating a plurality of latches.
U.S. Pat. Nos. 3,119,318; 3,507,593; 4,423,851; 4,484,813; 4,551,016; 4,619,526; 4,669,870 and 4,704,028 relate to vacuum blankets and the like
U.S. Pat. No. 4,967,230 discloses a registration system for light exposure apparatus employing a glass frame and a vacuum blanket and U.S. Pat. No. 4,935,773 discloses another type of vacuum blanket.